1. Field of the Invention
The present invention relates generally to chiropractic testing, chiropractic diagnosis, and the treatment of musculoskeletal disorders, and more particularly concerns a non-invasive method for determining the dynamic biomechanical characteristics of a musculoskeletal structure and an apparatus for use in carrying out the same.
2. Description of the Prior Art
The chiropractic art is generally concerned with treating misaligned body structures by manually manipulating the various joints in the human body. Of more specific interest in the art, however, is the spinal column which is comprised of several interconnected bones or vertebrae. Unlike other, less critical body structures, the spinal column must be treated or manipulated with extreme caution because of its link with the central nervous system.
The human spine is susceptible to many different pathologic abnormalities including misalignment, miscellaneous trauma and pain, and degeneration as a result of age or disease. By employing various physical therapy techniques, though, a chiropractor, or one skilled in the chiropractic art, may be able to successfully treat a pathologic spine. Successful treatment will not only relieve any pain or discomfort that the patient might be suffering, but will also improve the overall quality of life of that patient.
One common spinal-adjustment technique involves applying thrusts or forces to the afflicted region of the spine. In particular, this technique involves either "mobilizing" the spine (i.e. passively moving the spine with relatively slow cyclic or oscillatory motion), or "manipulating" the spine (i.e. applying an impulsive thrust or force in a well-defined direction to a specific region of the spine). Depending on professional affiliations, this technique is referred to as chiropractic adjustment, osteopathic manipulation, orthopaedic manual therapy, and/or spinal manipulative therapy.
There are several well known procedures for "manipulating" or administering impulsive thrusts to a spine. One method involves applying one or more rapid thumb thrusts to misaligned or afflicted vertebrae. Thumb thrusts, however, tend to be both imprecise in magnitude and location and tiresome to administer. Another technique involves using a manually operated chiropractic adjusting instrument. For instance, U.S. Pat. No. 4,116,235, issued to Fuhr et al. ("Fuhr"), discloses such an instrument. In particular, Fuhr describes a variable, spring-loaded apparatus for delivering a controlled and predetermined impact force or thrust. Heretofore, however, the Fuhr device has been used solely as a therapeutic device for adjusting misaligned vertebrae and has not yet been used as a diagnostic instrument for determining the dynamic biomechanical characteristics of a musculoskeletal structure (or spine).
The ability to quantify the dynamic biomechanical characteristics of the spinal column of a particular patient provides a chiropractic practitioner or spinal surgeon with several advantages over the current state of the art. Some of these advantages include, but are not limited to: providing a means for obtaining a detailed description of the mechanical status (or health) of the spinal column; providing a method for diagnosing any abnormalities in the spine; providing a way to access the effectiveness of continuing spinal manipulative therapy; and providing a means for appraising the successfulness of spinal fusion surgery. Moreover, by identifying the natural frequency of a spine and by "tuning" impulsive thrusts to that frequency, a chiropractic practitioner can maximize the motion response of the spine while minimizing the magnitude of the thrust. Such a procedure would not only enhance the effectiveness of spinal manipulative therapy, but would also decreases the possibility of damage to the spine during treatment. Furthermore, although the determination of the dynamic mechanical characteristics of a spinal column is an especially important diagnostic tool in the chiropractic art, the various procedures and devices discussed herein have equal applicability to all musculoskeletal structures, and, thus, should not be construed as strictly limited to the chiropractic art.
A chiropractic practitioner can also use mechanical stimuli and natural frequency information to prevent musculoskeletal atrophy and to even stimulate bone formation. There several patents and publications that disclose various methods for maintaining or promoting bone tissue growth, but none of these references disclose a method for preventing musculoskeletal atrophy and stimulating bone formation by subjecting the musculoskeletal structure to thrusts delivered at the natural frequency of the structure. For instance, U.S. Pat. No. 5,103,806, issued to McLeod et al. ("McLeod"), discloses a method for promoting bone tissue growth by subjecting a bone to a mechanical load having a low amplitude and a relatively high, but non-specific, frequency (i.e. a frequency range of between about 10 and about 100 hertz). The natural frequency of most musculoskeletal structures, however, is below or at the lower end of this range. More significantly, though, the McLeod patent merely designates a preferred frequency range for treating all bone tissue and does not contemplate or suggest first determining the natural frequency of the particular bone tissue under consideration and then stimulating that bone tissue at its natural frequency.